The present invention relates to a new and improved construction of an injection syringe, also simply referred to as a syringe, for the successive injection of two liquids or agents into the blood vessels of living bodies or the like.
In its more particular aspects, the syringe for the successive injection of two liquids, especially although not exclusively, a liquid contrast agent or medium and a flushing agent or medium, into the blood vessels of living bodies, is of the type comprising a cylinder provided at one end thereof with an attachment or connection flange and at the other end thereof contains, at the region of an outlet or discharge opening, a catheter connection or equivalent structure. A piston member can be inserted into the cylinder, so as to be displaceable therein in a liquid-tight manner.
Particularly in the field of computer tomography an injection technique is gaining increasing importance, wherein immediately after injecting a contrast medium there is injected a physiological saline or salt solution. However, with the state-of-the art syringes, for instance as disclosed in Swiss Patent No. 580,427, granted Aug. 31, 1976, there only can be injected during one working operation a single liquid. Thus, there must be employed in each case two syringes, each of which is filled with a respective liquid and each of which is provided with a respective drive. Apart from the high costs involved with the employment of two syringes and two drives the use of two systems requires a correspondingly greater expenditure in terms of servicing and operating the same as well as monitoring such systems.